Abstract: Carburetors are tested using a flow-testing bench which includes a first and second critical flowthrough nozzle arrangement, arranged upstream and downstream, respectively, of the carburetor, and a third critical flowthrough nozzle arrangement which by-passes the carburetor intake pipe. The first and third nozzles are adjustable in cross-section, and are used to regulate the carburetor air throughput and the pressure downstream of the carburetor. These parameters, along with the carburetor throttle valve position, are varied to simulate various operating flow conditions of the carburetor. The fuel delivery rate is measured, and the fuel-to-air ratio determined, for such operating conditions to assure proper functioning of the carburetor. The method permits dynamic measurements to be made on a carburetor being tested.

Abstract: This invention is an apparatus for testing the volume of a fluid medium flowing through a variable cross-section throttling point, such as the air throttle duct of a carburetor for an internal combustion engine. The fluid medium to be tested enters a primary duct of the present invention which has an input pressure regulator followed by two constant cross-section nozzles through which the fluid medium must pass. A flow branch duct which includes a second pressure regulator and the flow device intersects the primary duct for fluid transmission at a point between the two nozzles. The second pressure regulator is at the input to the test device. A pressure gauge is provided at the intersection of the main duct and branch duct. The indicated pressure is inversely proportional to the fluid flow volume through the test device.

Abstract: A fluid flow test stand for measuring the flow cross-section of a specimen, such as an automotive carburetor, is provided with a test nozzle arranged at a fluid flow outlet of the specimen. The test nozzle has characteristic quantities of inlet pressure and flow volume. In accordance with the invention, control means are provided for varying either the inlet pressure or flow volume of the test nozzle independent of the outlet pressure and flow volume through the specimen.

Abstract: A method of testing a device, especially a carburetter of an internal combustion engine, in which a predetermined constant fluid flow is imposed through the device, the fluid pressure at the inlet of the device is measured and the measured fluid pressure at the inlet is compared with a desired value of fluid pressure at the predetermined flow-through, whereafter an adjusting means is adjusted until the measured value is substantially equal to the predetermined value; and an apparatus for carrying out the method.